1. Field of the Invention
The present invention relates generally to the fields of dermatologic surgery, hair transplantation and medical devices. More specifically, the present invention relates to a novel dilator/hair implantor device for use during hair transplantation procedures.
2. Description of the Related Art
Hair transplantation using hair grafts (standard, minigrafts and micrografts) has increased in popularity in recent years. The goal of hair transplantation using hairgrafts is to replace scarce or lost hair in one area of the scalp with hair taken from another area. Although numerous descriptions of techniques exist, the procedure is basically the same in most instances. Usually, the hair to be transplanted is taken from the back of the head where it is generally in abundance, even in those individuals with very thin or absent hair elsewhere. This is typically accomplished through removal of a relatively narrow strip of scalp from that area. As the resulting wound is likewise narrow, it can be closed by suturing. The resulting scar is minimal and the scar is generally well hidden by the surrounding hair. Many tiny hair grafts are then taken from the strip of scalp, using either a scalpel or a razor blade. These can be micrografts (1-3 hairs), minigrafts (usually 4-6 hairs) or standard grafts (up to 4 mm). These hair grafts are implanted into the desired area of the scalp, usually in front. Alternatively, hair grafts can be obtained by using a punch instrument (either manual or electric) which is a round cutting instrument, analogous to a cookie cutter, and excising hair grafts directly from hair bearing skin from the scalp or other hair-bearing regions of the body. These hair grafts can then be directly implanted as standard grafts or cut into smaller grafts, i.e., minigrafts or micrografts as desired. From this point on, the surgical techniques used varies.
There are 50 to 1,000 donor grafts per hair transplant session, which are implanted into an equal number of recipient sites. Before any hair graft can be transplanted, a small hole or opening into the scalp must be made. Recipient sites can be prepared with a variety of instruments: needles, small blades, or small punches. Appropriate size needles (to create microholes) or scalp blades (to create slits), as well as small skin punches (to create standard holes) have been used in the past by hair transplant surgeons.
Slits or microholes are typically placed between existing hair follicles or on the periphery of the scalp, performed with sharp scalpel blades or with 20, 18, 18 Nokor, or 16 Nokor needles. These slits or microholes are sometimes employed in individuals with earlier thinning or previous micrograft sessions. On the other hand, holes (1 mm to 4 mm in diameter) are sometimes used in individuals with starkly bald scalps or to remove bald skin from between plugs. However, the creation of holes, including the removal of bald scalp skin is more time consuming. Grafts generally are ejected, i.e., "pop out of the scalp" more easily from holes than from slits, but compression often results from grafting into slits. Some surgeons place a small notch at one end of the circle to alter the hole into an ellipse, sigma shaped or "q" shaped or place a second small slit, using a small blade, at an angle relative to the initial slit with the intention of greatly decreasing graft extrusion and compression. One may employ slits and holes in different recipient areas in the same patient, or in subsequent sessions in the same area. Hair graft insertion is typically performed using forceps or similar grasping instruments to take hold of the hair graft and push the graft into the recipient slit or hole while avoiding compression of the hair root.
After the cuts in the scalp have been made, some surgeons will then insert an instrument into the hole in order to dilate the hole, i.e., use a dilator. Examples of prior art dilators include small diameter solid metal tubes and wooden dowels. The objective when using a dilator is to facilitate placement of the hair graft which must be gently placed into the hole in the scalp. Microdilators, by expanding the size of recipient sites (holes, slits and microholes) facilitate micrograft placement, and can be helpful in some hands. Dilators are used to keep the donor slit or hole open, facilitate graft insertion by stretching the recipient site, act as markers for accurate spacing, aid in hemostasis, and prevent missed recipient sites and aid in quantifying the number of recipient sites prepared. However, because dilators involve two additional steps in hair transplantation, i.e., hair placement and removal prior to graft insertion, many surgeons find these extra steps time consuming.
Although surgeons have used dilators, it is time consuming for the hair transplantation surgeon to place the dilators into the scalp and then remove them. Although dilators save time during the actual placement of each graft into its recipient site, overall, the use of the dilators is viewed by many of those having ordinary skill in this art as taking more time than is desirable. Mainly for this reason, dilators are often omitted despite the above advantages.
Eberhard (German Patent No. 1,953,026) discloses a hair implantation device. Applicant's invention is an improvement over Eberhard by combining the necessary actions of cutting, dilating and inserting of the tissue into the scalp. Dilation is an important feature of tissue grafting to, e.g., minimize bleeding, ease the placement of grafts by making grafting faster and less traumatic, and prevent subsequent compression. The wedge design of Applicant's hairplanter is important for dilation and for gentle transfer, features not addressed and in some ways opposite of what Eberhard designed.
Applicant's device facilitates a gentle transfer of the hair follicle not necessary with artificial hairs, with efforts to minimize vertical and lateral forces through employment of Applicant's wedge design so at to dilate the recipient site and facilitate a gentle sliding implantation of graft. By contrast, Eberhard's claims relate to foreign/artificial hair that has different handling and physical requirements. This is illustrated clearly by the impaling of the artificial graft which is an integral feature of technique of transplantation disclosed in Eberhard and the anchor that has no biological counterpart for tissue transfer. Moreover, Applicant's device is not limited structurally to a cylindrically symmetric device like the needle/cannula system disclosed by Eberhard.
The actual insertion or placement of the hair grafts into the scalp hole or slit is the most difficult and important part of hair transplant surgery. The prior art is deficient in the lack of simple, cost-effective means of dilating hair graft sites and easily inserting hair grafts during hair transplant surgery. The present invention fulfills this longstanding need and desire in the art.